I may break code
Under a hand rinse sink (one DFU) I need to install a "close elbow" in order to hide the plumbing from view. The sink is on a slim counter and they don't want to see the pipes under the counter. The plan is to send the waste straight back to the wall, immediately after it drops through the counter.
So there would be a tight turn, not a long sweep.
Luckily, I have room in the cupboard before the wall, to put an air intake so the pipe can grab some air (or let some out) before the P trap. Like an air gap.
This application is like the kits sold for wheelchair access. I notice that the big manufacturers all sell a close elbow kit, for $100, and just to get a single component of the kit costs $100 too!
The little drawing might illustrate well what I am thinking.
Since the sink has an overflow, and the waste line has an air intake, I am thinking that this whole setup will drain well. Is this the best compromise?
What say you?
"Luckily, I have room in the cupboard before the wall, to put an air intake so the pipe can grab some air (or let some out) before the P trap. Like an air gap."
I dont think you would need that. this seems to be a common theme with H/C sinks. Im sure it will be ok.
I'm thinking of the drain/overflow assembly on a tub - which has an even tighter elbow from the drain, if you think about it.
I also think you'll be fine.
Then again, I'm not a plumber.
Dave, if that drain is on it's own, without tying into another horizontal drain, then you're fine.
In My state it's ok to use a short sweep on single drains horizontally as long as it's not connecting to anything else at that 90.
A chrome "bottle trap" would have very little exposure, it the waste outlet is high enough. Otherwise an offset handicap sink drain, with a 1 1/4" x 12" tailpiece tube threaded into the outlet and going through the wall would work, assuming you intend to install the trap behind the wall.